Animated terrain - bug, my mistake or bad docs?

[Khoth]

I'm trying to make a terrain type that looks like the laser energy source, but not animated.

 

begindefineterrain 422;

import= 125;

te_which_sheet = 790;

te_ed_which_sheet = 689;

te_which_icon = 8;

te_ed_which_icon = 8;

te_name = "Alarm";

 

As far as I can see, animation is done using the te_anim_steps property, which I don't use here (terrain 125 is one of those terrains that a lot is based on, and isn't animated.

 

However, in the scenario the terrain comes out animated for some reason.

 

What's going on?